The present invention relates to a method for securing the operation of a telecommunications network in a cellular radio system, in which telecommunications network base stations are connected in series in such a way that at least one base station serves as a repeater for telecommunication signals of preceding base stations. The invention further relates to a base station arrangement in a cellular radio system, comprising means by which the base station can establish a radio connection with active-radio units currently located within its predetermined radio coverage area, and means by which the base station can repeat signals transmitted by other base stations in the telecommunications network interconnecting them.
Previously known are telecommunications networks for cellular radio systems in which base stations are connected in series in such a way that a base station in the network serves as a repeater for telecommunication signals from preceding base stations. In such a prior art telecommunications network, data transmission between the base stations is secured by way of galvanic relay connections. When a base station in the network ceases to operate on account of a mains disturbance, for instance, thereby also ceasing to regenerate the telecommunication signals from preceding base stations, a relay incorporated in the base station disconnects the base station from the telecommunications network in such a manner that the base station is bypassed by way of a galvanic connection.
The most significant drawback of the above prior art telecommunications network is that it cannot compensate for attenuation of the signal level brought about by the network cabling. This attenuation and disturbance induced by the network can be significant, since comparatively lengthy transmission cables must often be employed in telecommunications networks of cellular radio systems on account of the wide geographic area covered by the network. Consequently, there is a danger that if a base station forming part of the network ceases to operate and is thereby rendered incapable of regenerating signals delivered by preceding base stations in the network, the operation of the entire telecommunications network ceases, as its cabling attenuates the level of the transmitted signals too much for the base station that is next to the failed base station in the network to be able to identify the signals supplied. In other words, a blackout is created in the network at the failed base station. The signal level is further affected by the above-mentioned galvanic connection, which may cause considerable attenuation.